1. Field of the Invention
This invention relates to a trailer for receiving, transporting and unloading large cylindrical bales of agricultural products, and, in particular, to a cylindrical bale trailer which uses the force of gravity to unload the bales so that the round side of the bale is always in contact with the ground, and which is capable of automatically unloading bales which are out-of-round, i.e., flattened on one side, and resistant to rolling motion.
2. Description of Related Art
Present farming methods involve the processing of hay and other agricultural products in the field into large cylindrical bales having a round side surface and two flat end surfaces, which are approximately 4-5 feet in length, 5 feet in diameter, and weigh as much as 2000 pounds. Such bales of agricultural products are used as feed for livestock. Typically, cylindrical bales are prepared and stored in the field for many months before being used as feed. In order to protect the bales from rain during storage, the bales are made with a tightly wound round surface which tends to shed water better than the flat end surfaces. Therefore, it is desirable to store large cylindrical bales with their round surface touching the ground, i.e., the watershed orientation. Moreover, when the bales are distributed for use as livestock feed, it is also desirable to place the bales with the round surface on the ground because the bale ends are the desirable places on the bale for livestock to feed.
The size of these cylindrical bales makes manual handling by laborers impractical, if not impossible, and the loading, transporting and unloading of such bales has become a problem which is not effectively or efficiently solved by utilizing conventional farm equipment. A need for specialized equipment for loading, transporting and unloading such large cylindrical bales has been recognized, and a number of specialized trailers have been previously proposed for this purpose. However, the specialized bale carriers known to applicant have disadvantages. Some of the prior devices such as disclosed in U.S. Pat. Nos. 5,123,800 and 5,137,412 are impossible to load using conventional farm equipment, e.g., a conventional 3-point hitch spear on a tractor rear or a spear mounted on a front end loader, because of the above-ground height and/or the orientation of the bale carrying cradle on the trailer. Some of the prior devices such as disclosed in U.S. Pat. No. 4,261,676 require a special hydraulic lift apparatus to load the bales and hydraulic ram apparatus to unload the bales. Some of the prior devices such as disclosed in U.S. Pat. No. 4,411,572 employ complex mechanical linkage to enable the bale cradle to rotate between transverse and longitudinal orientations to the trailer frame.
However, one problem which the prior devices do not discuss or attempt to solve is the settlement of the bales during storage and/or transport due to their great weight. This settling causes the part of the bale in contact with the ground or the carrying surface of a cradle to flatten, or go out-of-round. A flattened or misshapen bale poses a special handling problem because, when combined with the great weight of the bale, it causes the bale to resist rolling off of a bale cradle which is designed for gravity unload such as disclosed in U.S. Pat. Nos. 4,138,159, 4,411,572, 5,123,800, and 5,137,800. Because such flattened and out-of-round bales resist rolling and, thereby, will not self-unload under the force of gravity, these prior devices require additional handling and/or special equipment to unload.